Nailing machine



Sept. 17, 1957 Filed Sept. 1. 1954 AL A. CAVANAUGH NAILING MACHINE 3Sheets-Sheet 3 INVENTOR. ARTHUR A. C4IJ4NAUGH 2,806,219 NAILING MACHINEArthur A. Cavanau'gh, Alameda, Calif. Application September 1, 1954,Serial No. 453,605 2 Claims. (Cl. 1-46) This invention relates to anailing machine. More particularly, it relates to certainimprovements onprior nailing machines, particularly that described and claimed In myprior Patent No. 2,573,540, granted October 30 1951, and entitledNailing Machine.

In a, nailing machine intended for nailing floors, such as thatdescribed in my prior patent above referred to, it is important thatnails be supplied to a nail driving or nail set passage in the drivingmechanism in such manner that, whenever the driving plunger is moveddown-I wardly, as by means of a blow of a hammer, there is always. onemail but only one nail in the nail set passage. It IS exceedinglyimportant that the nail feed means provided for this purpose operate insuch a r to eliminate as completely as possible, the likelihood that asecond nail will be supplied to the nail set passage before thepreceding nail has been completely driven into the floor.

The nailing machine of my prior patent has achieved considerable successin this and other respects and constltutes a very substantialimprovement over prior nailmg machines. However, it is subject tocertain disada vantages under certain conditions. Thus, the last nailinthe nail feed mechanism, which is the next nail to be delivered to thenail set passage and to be driven into a floor, is preferably held inposition by magnetic means and is released mechanically. Sometimes thisnail is dislodged prematurely from the magnetic nail-holding means byreason of vibration and shock resulting from operation of the machine.At other times the nail held by the magnetic holding means is dislodgedprematurely by the mechanical release means, by reason of the fact thatthe preceding nail is driven into a floor by degrees With more than onestroke single stroke of the hammer. If the machine is used with moreblows of a hammer are required to drive a single nail into :a floor, andthe mechanical nail release means may be actuated prematurely, beforethe preceding nail has been completely driven into a floor. 1

machines is that the recoil of the nail driving plunger frequentlyactuates the nail release means prematurely.

It is an object of the present invention to provide an improved form ofthe nailing machine.

Another object of the invention is to provide a nailing machine fordriving nails into floors, which eliminates or minimizes disadvantageswhich have occurred in practhat of my prior patent above-identified.

lodged by shock and vibration.

A still further object of the invention is to provide .a

nailing machine of the general character and for the general purposedescribed which employs means for semanner as of a hammer rather thanbya long nails, e. g., with eight-penny finishing nails, two 1 Another,and a very serious difficulty with prior nailing Patented Sept. 17, 1957curely holding the next nail to be driven until the preceding nail hasbeen completely driven into a floor.

A further object of the invention is to provide a nail driving machinewhich can be used with relatively long nails such as eight-penny nails,without the disadvantage of premature release of nails.

Yet another object is to provide a nail driving machine in which therecoil of the nail driving plunger does not actuate the nail releasemeans prematurely.

These and other objects of the invention will be apparent from theensuing description and the appended claims.

One form of the present invention is illustrated by way of example inthe accompanying drawings, in which- Figure 1 is a view, partly in sideelevation and partly in vertical section, of the, nailing machine of thepresent invention. V

Figure 2 is a view in vertical midsection of the nail driving mechanismof my nailing machine, such view being in the plane of nail deliverychutes and showing the nail driving plunger in its normal, up position.

Figure 3 is a view similar to that shown in Figure 2, but showing thenail driving plunger in its down position, showing a nail completelydriven into a floor and showing the next succeeding nail released by thenail feed means.

. Figure 4 is a view in front elevation: of the nail driving mechanism,as seen along the line 4.4 of Figure 1, but shown on a larger scale.

Figure 5 is a fragmentary view similar to that shown in Figure 4, butpartly broken away to reveal more clearly the operation of thenail-holding and release mechanism, and showing the latter in therelease position.

Figure 6 is a horizontal section taken along the line 6+6 of Figure 4.

Figure 7 is a horizontal section taken along the line, 77 of Figure 5. v

Figure 8 is a fragmentary view in side elevation as seen from the leftof Figure 4 but with the side plates removed.

Referring now to the drawings and more particularly to Figure 1, thenail driving machine of the present invention is there illustratedand'is generally designated by the reference numeral 10. It comprises anail supply 11. Spaced, parallel side plates 13 are provided which aredetachably secured, as by means of screws 13a, to

the nail driving mechanism 12 and to the nail supply assembly 11, suchplates serving to hold together the nail supply assembly 11 and the naildriving mechanism 12 and to provide a sturdy, rigid unitary structure.

The nail supply assembly 11 may be generally the same as that describedand illustrated in my prior Patent No. 2,573,540, and it is so shown inFigure l of the present application. asupply of nails which is formed atthe lower edge of its sloping bottom with a slot 15 to allow nails todrop into an upper nail chute 16. The latter is formed with alongitudinal slot 17 of a width to allow the bodies of finishing nails18 to pass but to hold their heads 18a and suspend them in the mannerillustrated. However, other types of nails than finishing nails may alsobe used in the machine of the present invention.

A lower chute 19 is provided which is formed of two bars 19 spaced apartto provide a longitudinal slot 20, and it is secured to the upper chute16, as by means of screws 21. The lower chute 19 and its slot 20constitute a continuation of the upper chute 16 and its slot 17, re

spectively. A U-shaped shingle nail guard 25 and a de:

It includes. a nail hopper 14 for holding ing elements in the nailsupply assembly of my prior patent. Very briefly, it is the function ofthe nail guard 25 to prevent passage of nails, such as shingle nails,having larger heads than desired, to the lower chute 19, and it is thepurpose of the deflector plate 26 to deflect nails which lietransversely in the chute 16.

A vertical frame bracket or plate 27 is provided to which the sideplates 13 are aflixed, and a bin 28 is fixed to the plate 27 beneath andin registry with the shingle nail guard 25 and the deflector plate 26,so as to receive nails which are deflected or removed by the latterelements. Casters are provided, one of which is shown at 29, to renderthe machine more easily' mobile. A hinged retarding plate is provided at30 which serves the purpose of retarding somewhat the flow of nails fromthe hopper 14 into the upper chute 16 to prevent piling up and jammingof nails in the chute 16. 1

Referring now more particularly to Figures 2 to 5, the nail drivingmechanism-12 comprises a tubular bar- 'rel 35 of sturdy, thick-walledsteel construction and formed with a longitudinal, axial passage 36. Thelatter is best shown in Figures 2 and 3 and is formed with internalshoulders at 37 and 38, and with an accurately machined throat portionat 39, to slidably receive a nail driving plunger 44, which is describedin detail hereafter and is referred to as the driver. Beneath the throatportion 29, the passage 36 is of wider diameter at 41 and provides asection to which nails are delivered in the manner hereinafterdescribed. At its lower end, the passage 36 is formed with a shoulder42, and with a widened portion 43 which receives a detachable nail setplug 44, which is described in detail hereinafter. At its open upperend, the barrel 35 is provided with a detachable cap 45 'which is formedwith an opening 50 to slidably receive the upper end of the driver 40,and which is secured to the barrel 35 by means of countersunk cap screws51.

The nail-set plug 44 has a body portion 52 of cylindrical shape and of adiameter to form a sliding fit within the lower end portion 43 of theaxial passage 36, and it is formed with an annular groove to receive acompressible friction ring 53 which frictionally engages the side wallsof the cavity 43 to hold the cup 54 in place and to prevent it fromdropping out by gravity but which nevertheless permits ready detachmentof the plug by hand when so desired.

The plug 44 is formed at its lower end with a widened head 54 whichabuts the bottom surface of the barrel 35, and it is also formed with anaxial passage 55 to receive a nail as shown at 18 in Figure 2, and atits upper end it is formed with conical seating cavity 56.

The driver 40 is constructed in two parts, including a lower portion 57of cylindrical shape and of a diameter to be slidably received in thethroat 39 of passage 36, and an upper portion 58 which is also ofcylindrical shape and of a diameter to be slidably received in theopening 50 in cap 45. At its upper end, the lower portion 57 of driver40 is threaded as illustrated, and is in threaded engagement with a cammember 59 which is integral with and at the lower end of the upperportion of 58 of driver 40. As illustrated, the cam portion 59 has afrusto-conical lower end 65 which constitutes a cam rise and acylindrical upper end of a diameter somewhat less than the insidediameter of the passage 36. The cam member 59 is also formed with ashoulder 67 which provides a seat for a strong spring 68, which servesas a shock absorber during operation of the machine.

At its extreme lower end, the driver 40 is formed with a nail set 69which is slidable in the nail set passage 55 of the plug 44, and whichis tapered at 70 at its lower end, as illustrated, to form a bluntpoint. At its junction with the nail set 69, the driver 40 has afrusto-conical shape as illustrated at 71, for seating in thefrusto-conical seat 56 of plug 44. An expansion spring 72 is providedwhich is compressed between the lower end of cam diameter of the head18a of the nail.

59 and the shoulder 38. The spring 72 urges the driver 40 to andnormally holds it in the up position illustrated in Figure 2. As is alsoshown in Figures 2 and 3, a lateral passage 73 is formed in the lowerend of the barrel 35, for supplying nails as they are dislodged from thenail feed mechanism to the nail set passage 55. The nail feed mechanismwill now be described in detail.

The barrel 35 is cut away and machined at one side (on the right asviewed in Figures 2 and 3) to provide a cavity 80 which receives a lowerblock 81 and an upper block 82. These blocks are secured within thecavity 80 against its vertical face 80a, by means of countersunk capscrews 83. The lower block 81 has a slot 84 formed therein, which isbest shown in Figures 4 and 5 and which serves to receive and pass thelower ends of nails 18 as they reach the bottom of the lower chute 19,and it is also formed with a passageway 85 formed with a slanting groove86, which communicate with the lateral passage 73 in the barrel 35.

The upper block 82 has a guide rod 96 fixed thereto, extending upwardlyand forwardly therefrom and overlying the chute 19, the purpose of whichis to guide nails into the nail holding and release mechanism. The block82 is formed with a U-shaped recess 91 (Fig. 4), having a slanting topportion 92, against which the lower end of the chute 19 bears and towhich the chute is fixed by any suitable means, such as the screwsshown. A groove 93 is formed in the slanting top .portion 92 forclearance of nail heads 18a, and at its lower edge the slanting topportion 92 terminates in a semi-circular shoulder 94, and rearwardlythereof or to the left as viewed in Figures 2 and 3, the recess 91 has ahorizontal top portion 94. The block 82 is also formed with a horizontalslot which slidably receives a nail-holding bar 99.

' The nail-holding bar 99 has a nail-holding notch 100 formed therein atits center. The notch 100 is of sufficient width to receive the shank ofthe nail but less than the 7 Hence the notch 100 will hold and suspend anail as illustrated in Figures 3 and 4. The nail-holding bar 99 slidesin the slot 98 in block 82, as explained above, and it also slides in acompanion slot 101 (Fig. 6) formed in the vertical face "80a of thecavity 80. Immediately above and adjacent press-fitted into andprotrudes from the face 80a.

" screw 105 is threaded through the head portion so as to bear againstthe block 82 as illustrated in Figures 4 and 6. A lock nut 106 isprovided to lock the set screw 105 in adjusted position.

' which is fixed to the adjacent, flat side of the barrel 35,

as by screws 109. The spring 108 normally holds the nail-holding bar 99in and at all times urges it to the position illustrated in Figures 4and 6 wherein the notch coincides with the groove 20 in lower chute 19.The notch 100 is, therefore, normally in a position to receive a nail 18and to hold and suspend it as illustrated in Figure 4.

-A lever 110 is provided which is pivoted at 114 in a slot 115 formed inthe side' wall of the barrel 35, such lever having a curved inner edge116 which slopes to a high point 117 at its lower end. The lever 110 isalso provided with a projecting stud 118 which contacts or lies closelyadjacent to the leaf spring 108, and is normally seated in a notch 119formed in the barrel 35.

In operation, the nailing machine above described and illustratedfunctions as follows:

Referring now more particularly to Figure 1, a supply The head portion104 is notched at 107 to slidably receive the lower end of a leaf spring108 of finishing nails such as shown at 18, are provided in the hopper14 and are fed automatically by the nail supply assembly 11, includingthe upper chute 16 and the lower chute 19 to the nail driving mechanism12. The moving parts of the nail drivingmechanism 12 are normallymaintained in the positions shown in Figures 2, 4 and 6. That is, theexpansion spring 72 holds the driver 40 in the up position illustratedin Figure 2, and the leaf spring 108 holds the nail-holding bar 99 inthe position shown in Figures 4 and 6. It will, therefore, be apparentthat, at all times, and until the driver 40 is struck a blow by a hammeror is otherwise moved downwardly from the position shown in Figure 2,anail 18 will be suspended from the bar 99 in the manner illustrated inFigure 4, but such nail will be prevented from dropping into the lateralpassage 73 (see Figure 2) by reason of the fact that the head 18a of thenail is of greater diameter than the width of the notch 100 in the slidebar 99. It will, therefore, be apparent that the next nail to be drivenis held by positive, mechanical means until it is ready for release, andthat it cannot be shaken loose.

Assuming that a nail 18 is in the nail set passage 55 in the plug 44, asillustrated in Figure 2, and that the driver 40 is moved downwardly by ablow from a hammer, the nail set 69 will enter the nail set passage 55and will drive the nail 18 into a floor as illustrated in Figure 3.

Assuming that a single blow of the hammer drives the nail completelyinto the floor in the manner illustrated in Figure 3, the expansionspring 72 will, of course, restore the driver 40 to its up positionshown in Figure 2. The shock of impact as the plunger reaches the upperlimit of its travel will be absorbed by the shock absorbing spring 68.Meanwhile, during the down-stroke of the driver 40, the cam member 59will, during its last increment of movement, contact the high point 117of lever 110 as illustrated in Figure 5, and will rock the lever 110 tothe left or clockwise as viewed in Figure 5. This will force the leafspring 103 in a like direction, which will carry with it thenail-holding bar 99 to the extreme lefthand position shown in Figures 5and 7. This movement of the bar 99 will carry with it the next nail 18,i. e., the nail lodged in the notch 100. During such movement, the nail18 will be forced outwardly, or to the right as viewed in Figures 2 and3, by reason of the rise 102a in cam groove 102 and by reason of theball bearing 103. The nail 18 is, therefore, located in registry withthe notch 103a in bar 19a (see Figures 6 and 7), it is dislodged fromthe notch 100 in bar 99, and it is free to drop into, and does in factdrop into the passage 86 in the lower block 81 and the lateral passage73 in the barrel 35, to the position shown in Figure 3. The nail is,therefore, in readiness to drop into the nail set passage 55 when thedriver 40 returns to its up position illustrated in Figure 2. Thenail-holding bar 99 returns to its normal position shown in Figures 4and 6, as the driver 40 returns to its up position and receives the nextnail in the chute 19. Any tendency of the preceding nail to relodge inthe notch 100 and to return with the bar 99, is prevented by the ballbearing 103, which traps the preceding nail. Thus, misses are prevented,and a nail is delivered to the nail set passage 55 every time thatpassage is cleared by driving the preceding nail into a floor.

Another consideration of great importance is that a nail lodged in thenotch 100 of bar 99 be released and delivered to the barrel 35, when butonly when the preceding nail has been completely driven into the floor,and only when the driver 40 has been driven to the -bot tom of itsdownstroke. Two sources of difiiculty exist in this connection:

First, the recoil of the nail driving plunger (i. e., the driver 40 inthis instance) causes it to undergo a partial downstroke, which mayactuate the nail-holding and release mechanism prematurely. Second, whenlonger nails are used than conventional hardwood floor nails (e. g., tWoinch, eight-penny finishing nails instead of the conventional one inchhardwood floor nails), several strokes of the hammer may befrequired todrive each of the longer nails into a floor, and the nail-holding andrelease means may be actuated after, say, the first or second blow ofthe hammer and before the preceding nail has been driven completely intoa floor. In either casei. e., premature release of the next nail becauseof recoil, or because of .the necessity of driving a nail by incrementswith more than one hammer blowjamming of two or more nails in the nailset passage will result.

These difliculties, which are real and important in practice, areobviated by the nail release mechanism of the present invention. As willbe apparent from an inspectionof Figure 5, the lever 110 is rocked toactuate the nail-holding bar 99, when but only when the nail driver 40has traveled downwardly substantially to the limit of its downstroke.The driver 40 cannot, of course, travel close to the limit of itsdownstroke, unless the nail which it is driving has been completely, ornearly completely driven into a floor. Nor will the driver 40 bouncedown close to the limit of its downstroke owing to recoil. As aconsequence, recoil of the driver 40 will not actuate the nail-releasemechanism. And, if a nail is only partially driven into a floor, e. g.,half-way or two-thirds of the way into a floor, the nail-holding bar 99is not actuated, or it is moved insufiiciently to dislodge the nextsucceeding nail 18 from the notch 100. The bar 99 can be movedsufiiciently to release a nail from the notch 100, only when the nailset passage 55 has been cleared and the driver 40 is positively drivensubstantially completely to the limit of its downstroke.

For purposes of fine adjustment, the set screw 105 above referred to maybe employed. As is best shown in Figure 6, by loosening the lock nut 106the set screw 105 may be adjusted inwardly or outwardly. As will beseen, its inner end bears against the adjacent side of the upper block82, and by adjusting the set screw 105 inwardly or outwardly, the notchin bar 99 can be accurately aligned with the slot 20 in chute 19.

It will, therefore, be apparent that a nail driving mechanism has beenprovided which is relatively simple in its construction and operation,which has desirable features of adjustability, and which has the veryimportant ad vantage that, when a nail has been delivered to the nailset passage in readiness for driving into a floor, the next nail is heldsecurely in place by the nail-holding and release mechanism and is notreleased prematurely by reason of recoil of the driver or the need forseveral blows of a hammer to drive a single nail. By this means thelikelihood of jamming is greatly diminished.

Among other advantageous features of the machine may be mentioned thefollowing:

It is relatively small in size and is easily mobile. It can be takenapart with ease for inspection, lubrication, adjustment, repair andreplacement purposes. Fine adjustments can be made. Nails can be drivenat high speed with an assurance of accurate, straight nailing.

I claim:

1. In a nailing machine of the type comprising a barrel having alongitudinal driving passage and terminating at its lower end in a nailset passage for receiving and holding a nail in position for drivinginto a floor, a driver and nail set reciprocable in said driving passageand nail set passage, respectively, a nail feed bar reciprocablelaterally of said barrel between a normal position for receiving a nailfrom a nail feed and a release position for releasing such nail anddropping it into said nail set passage, and resilient means for normallyholding said bar in said normal position, the improvement whichcomprises cam means operated by said driver at approximately the limitof the downstroke of the driver to move the nail feed bar to its releaseposition, and adjustment means for adjusting the normal position of saidbar relatively to said release position.

2. In a nailing machine of the type comprising a barrel having alongitudinal driving passage and terminating at its lower end in a nail,set passage for receiving and holding a nail in position for drivinginto a floor, a driver and nail set reciprocable in said driving passageand nail set passage, respectively, a nail feed bar reciprocablelaterally of said barrel between a normal position for receiving a nailfrom a nail feed and a release position for releasing such nail anddropping it into said nail set passage, the improvement which comprisesa leaf spring attached at its upper end to said barrel and at its lowerend to one end of said feed bar to hold said bar in its normal position,cam means operated by said driver at approximately the limit of itsdownstroke to move the nail -feed bar to its release position, and a setscrew threaded through said one end of the feed bar and hearing at itsinner end against said barrel, said set screw being adjustable to varyand adjust the normal position of said feed bar.

I I 7 References Cited in the file of this patent UNITED STATES PATENTS

